Containers destined for local police forces were dropped from a helicopter into a Taliban-controlled area of Zabul province.

The coalition helicopter had intended to deliver pallets of supplies to a police checkpoint in Ghazni, a remote section of Zabul late last month.

By mistake they were dropped some distance from the checkpoint where it was taken by the Taliban, the Internal Security Affairs Commission of the Wolesi Jirga — the Afghan parliament's lower house — was told.

Hamidullah Tukhi, a local politician from Zabul, told the parliamentary commission that the consignment had been taken by a local Taliban commander.

A Nato spokesman said the pallets were carrying rocket propelled grenades, ammunition, water and food.

Afghan politicians have said they do not believe the drop was an accident.

Nato's General Carlos Branco blamed it on "human error" when the navigator confused two very similar grid references.

A spokesman at Nato headquarters in Brussels denied the suggestion the alliance had deliberately armed the Taliban. "We are aware of it but we are not fired up about it. It sounds like someone made a mistake. It was a cock-up rather than a conspiracy.

"The forces on the ground are working to get the message across that we do not deliberately supply the Taliban with arms."